Apparatus for making slide fasteners



APPARATUS FOR MAKING SLIDE FASTENERS Filed Dec. 5, 1932 Fig.2.

INVENTOR. Gearge H C er TTORNEYS.

' Patented Mar. 23, 1931.

UNITED STATES PATENT OFFICE nrrmm'rns FOR. MAKING SLIDE FASTENERS,

George H. C. Comer, Birmingham, England, as-

signor to Hookless Fastener Company, a corv poration of Pennsylvania This invention Application December 5, 1932, Serial No. 645,740

' In Great Britain December 9, 1931 2 Claims.

relatestov the die casting or molding of small articles from metal, wax, artificial resin and the like, and its principal objects are to provide an improved method of and 5 means for casting or molding sm'all intricately shaped articles close together in a continuous or semi-continuous operation. The invention eliminates the necessity of designing the shape of the article to suit known die casting or molding processes.

The inventio nis particularly adapted for the manufacture of the coupling parts for slide operated fasteners, and especially those having non-metallic fastening elements. While metals of low melting point may beused processes for mak in die casting ing such fasteners, I prefer to use non-metallic plastic materials. The coupling parts made of such materials are very strong and resistant to sired color.

wear and can be produced in any de- Furthermore, they are smooth and warm to the touch and do not possess the mechanical appearance of metallic coupling parts.

The invention in, its various aspe plates the use of a very wide range coming within the term pl rmo-hardening resinousm the of materials astics. It includes aterials for example,

phenol condensation. products; thermoplastic resins for example, cellulose acetate, ethyl cellulose, benzyl cellulose and-other resins which do not require heat plasti having been subje c shellac products may plastic caseinand also be used after cted to treatment so that they to harden;

do not'soften with a slight rise in temperature;

rubber, containing sul ing similar proper phur or a compound havties and mixed with other sub- I stances which determine and cold setting plastics the color of the product; for example, quick setting zinc oxychloride cement or the like.

The machine f0 for applying heat rial requires such used and pre ating the dies to m semi-continuous.

According to the comprisea die or mold r practicing the invention may in combination with means and pressure when the matetreatment, suitable means for with the desired matewith the class of material automatic means for operake the operation continuous or invention, the die consists of two or more longitudinally extending sections at least one of which ing adap ted to fit togethe of small side by side 0 or molds. By a flexible die-section is meant a die is. flexible, the said sections ber and to form a'number ompartments acting as dies component consisting of a plurality of die mem-j bers connected by means allowing relative fiexure,

cts conteme. g. an integral or attached flexible member. The sections have a series of recesses and projections corresponding in shape to the articles to be molded and when the several sections are brought into register they are passed through a tunnel-shaped. 5 holder, the molding material being im'ected through openings in the casing of the die holder and into the dies. The molds having been filled the combined die sections are withdrawn from the end of the tunnel-shaped die holder and the flexible sections are separated by bending them outwardly away from one another, thus allowing the cast or molded articles to fall away from the dies. The process may be made continuousby leading the separated ends of the die sections back again to the other or entrance end of the tunnelshaped die holder.

The flexible sections may be bands or strips of steel or other material having small pieces of metal (die members riveted and equally spaced thereon), the said die members being shaped to produce the desired shape of the fastener members and the bands which connect the die members being sufficiently flexible so that they may be bent in such a manner that the finished fastener may be withdrawn from same without damage; e. g. the sectional die members may be shaped like the dies shown in the pending United States application of William L. Gilmore Serial No.

565,781, filed September 29, 1931. 30

The small die members may be integral with the bands or strips and "in this case one face of each band will have teeth shaped to produce the desired fastener member.

Theinvention 'may be applied to the manufacture of interlocking fastener members for sliding fasteners and Fig. 1 of the accompanying drawing shows a diagrammatic perspective view of the flexible die sections and tunnel-shaped die holder for this purpose. In this casethe fastener members are cast or molded1 direct on' to the edge of the fabric tapes oi: stri gers.

2 is .a schematic ,view showing one form of filling the'die members.

.l is the tunnel-shaped die walls of which can be s the flexible die'sections holder, the opposite queezed together to grip 2, 3 and twhich are internally shaped'to suit the shape oi the fastener members 6, the top flexible die section 3 being shaped to provide the'r'ecess on one side and pro- '50 jection on the other side of each fastener mem-l' bert. The .iabrlc-tape 5 is fed into the tunnel in the direction of thearrow' l'and emerges from the other endwith the members cast on to the one edge as shown in the diagram.

a or

The artificial resin or other fluid or plastic is indected into the mold through holes 8 in the top of the die holder I, and during the injection period the die sections 2, 3 and 4 (which preferably are 5 continuous) are stopped, and hydraulic or other way in which the flexible die sections 3 separate from the finished fastener 5, 6, without damaging the recesses or projections on the heads of the cast members 6.

This separation is accomplished as indicated in its way to the mold and in the diagram, 1. e. when the finished fastener emerges from the die holder I it is pulled in a downward direction while the flexible die section 3 emerges from the tunnel and moves in an upward direction as indicated by the arrow 30. It

will be clear that the finished fastener stringer 5, a

6 and the flexible die section 3 are separating in the same manner as the stringers of a sliding fastener separate when the slider is moved to open 5 the fastener.

As mentioned above, the treatment of the material during application to the fabric tape varies in accordance with the type of material being used, and the means forsupplying the material to the dies will also depend upon the qualities of the material. For example, in the case of rubber compounds or ,the cold setting plastics, it will be necessary toshape the material into the form of soft pellets or beads, the volume of which is equal to the finished coupling part. These pellets may be introduced into the dies by any suitable mechanisfn and there receive the shape of the finished coupling part. In the case of rubber, it will be necessary to apply a suitable degree of heat and pressure to perfect the vulcanizing process and in the case of the thermo-hardening materials, it will also be necessary to apply the proper degree of heat and pressure. For this purpose, the die may be suitably heated and pressure may be exerted upon inwardly movable sides of the die holder.

For the purpose of supplying the thernio-plastic resins to the die, the material is preferably reduced to a highly'heated liquid condition so that it can be properly mixed. However, while being applied to the edge of the strip of fabri it is necessary that the material be relatively cool in order that it will not char the fabric. It is,

erefore, desirable to cool'theliquid material on the mold until it is in a semi-plastic condition. In-this manner also the escape of the material through the partsof the moldis avoid The device shown schematically in Fig. 2 has a to form fastener elements, said cylinder or container l I, where'the material is kept in a liquid condition and from which it. is pressed by a piston l2 into the channel I?! which divides into smaller channels I 4, which lead to still smaller channels l5, each supplying a die cavity l6.

The warm liquid material on its way to the die becomes plastic owing to the loss of heat in the various channels, and in the mold, and in this way, the molding and fashioning of the parts is effected without causing any damage to the strip of cloth through the heat.

The injection of the casting fluid, feeding of fabric. tape, gripping of mold and mold holder, and the movement of the flexible die section may be synchronized to allow the process to be made automatic, thus requiring little attention from the operator.

An important advantage of the above described method of manufacture of fastener members consists in the fact that the most efficient shape of fastener, i. e, with-recess on one side and'projection on the reverse side, can be employed, as distinct from the usual method of die casting or molding by means of a split plate mold in which case the fastener members can not take this form since the mold, which is rigid can not separate without breaking the castings. Also by the present invention no casting ridge is left on the operative portions of the fastener members.

I claim:

1. Apparatus for making fastener stringers of the kind having fastener elements secured in uniformly spaced relation on the edge of a flexible tape, comprising a die holder having a guideway, continuous series of flexibly connected die sections slidably mounted in said guideway and having cavities shaped to receive a flexible tape and to define mold chambers around the flexible tape for fastener-elements, means for supplying moldable materialflt'o said mold cavities, and means for connecting-the sections of each series to maintain them in uniformly ,spaced relation.-

7 2. Apparatus for making fastener stringers of the kind having fastener elementssecured in uniformly spaced relation on the'edge of a flexible holder having a tape, which comprises a 'die guideway, three continuous series of die sections having component parts adapted to mate together to form a series of mold chambers shaped die sections being slidably mounted in said guideway and having cavities communicating with the mold chambers to receive a flexible tape, and means connecting -the elements in each series to maintain them in uniformly spaced relation, said connecting means being flexible wherebyeach series of die sections is flexed away from the tape to release the molded fastener elements. a

GEORGE H. C. CORNER. 

